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Black Diamond Astro 300 Headlamp vs Nitecore NU21

Weight and specs compared for 2026 — and which one to choose.

Nitecore NU21 is the lighter option — 1 g lighter than the Black Diamond Astro 300 Headlamp (2% less weight). If grams matter to you, that is the one to beat.
Spec Black Diamond Astro 300 Headlamp Nitecore NU21
Weight 45 g · 0.045 kg · 0.10 lb 44 g · 0.044 kg · 0.10 lb
Brand Black Diamond Nitecore
Category Lighting Lighting
Black Diamond Astro 300 Headlamp
45 g

Ultralight 300-lumen headlamp at only 45g. Compact waterproof design with single AAA battery; perfect for thru-hikers minimizing base weight.

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Nitecore NU21
44 g

Ultralight USB-C rechargeable headlamp with 360-lumen white and auxiliary red beams, built for running and minimalist hiking.

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Black Diamond Astro 300 Headlamp vs Nitecore NU21: which should you buy?

If saving weight is your priority, the Nitecore NU21 wins — at 44 g it is 1 g (2%) lighter than the Black Diamond Astro 300 Headlamp (45 g). That said, the heavier option may justify the extra grams with more capacity, durability or comfort, so weigh the trade-off against how you'll use it.

See where both rank against everything else in this category on the lightest lighting page, or browse the full gear weight database.

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